1. Field of the Invention
The invention relates generally to a head-up display device and, more particularly, to a head-up display device used in a vehicle.
2. Description of the Related Art
A vehicle head-up display device may display vehicle driving data or other data in a main line of a driver's sight. Therefore, the driver may perceive important driving data and meanwhile keeping his eyes on the road to thus realize safe driving. Typically, a combiner that is allowed to provide a magnified image to a driver for a given field of view (FOV) is a critical component for a head-up display device. Therefore, it is important to optimize design parameters of the combiner to improve the optical efficiency and imaging quality of the vehicle head-up display device.